Pneumatic sanding wheel



April 1950 A. w. MALL 2,505,68fl

PNEUMATIC SANDING WHEEL Filed March 1, 1947 2 Sheets-Sheet 1 prfl 25,1950 A. w. MALL 2,505,530

PNEUMATIC SANDING Filed March 1, 1947 2 Sheets-Sheet 2 a LR INVENTOR.

Patente Apr. 25, 1950 lTED STATES ATENT ()FFICE PNEUMATIC SANDING WHEELArthur W. Mall, Flossmoor, 11]., assignor to Mall Tool Company, Chicago,111., a corporation of Illinois 2 Claims.

The present invention relates to a wheel that is provided with an aircushioned tread portion. The invention is primarily concerned withsanding wheels wherein a ring or band of an abrasive such as sandpaper,or the like, is mounted on the peripheral or tread portion of the wheel.This tread portion is backed up over substantially its entire area by anair chamber so as to give resiliency to the sanding surfaces of thewheel.

Among the principal objects of the present invention it is intended toprovide a relatively simple and inexpensive Wheel of this sort that ismade up of a relatively small number of parts that are easily assembledto form a strong and sturdy device. During use of a sanding wheel thewheel is caused to rotate at a relatively high velocity and the articleto be sanded is applied against the sanding surface of the wheel. Due tothe friction between the sanding surface of the wheel and the articleapplied thereto there is a constant tendency for the bands forming thesurface of the wheel to creep or move circumferentially about the wheel.This movement is prevented in the device forming the subject matter ofthe present invention in a manner to be described hereinafter. The aircushioning for the wheel periphery is provided without the use of aninner tube and the resulting structure is readily adapted for largescale production methods.

The foregoin constitute some of the principal objects and advantages ofthe present invention, others of which will become apparent from thefollowing description and the drawings, in which Fig. l is a sideelevational View of the sanding wheel forming the subject matter of thepresent invention;

Fig. 2 is a transverse sectional view through the wheel taken along theline 22 of Fig. 1;

Fig. 3 is a vertical sectional view through the wheel, the view beingtaken on the line 3-3 of Fig. 2; and

Fig. 4 is a fragmentary transverse sectional view through the wheel, theview bein taken on the line 4- of Fig. 1.

For purposes of illustration a single embodiment of the presentinvention will be described herein, though it is recognized thatmodifications will occur to those skilled in the art and it is intendedthat such modifications may be made Without departing from the scope ofthe invention.

Referring to the drawings the device forming the subject matter of thepresent invention comprises a wheel generally indicated at I10 (Fig. 2)that includes a hub portion II, a web I2 and a rim 13. The hub portion His apertured at M to receive a shaft.

As shown in Figs. 2 and 4 the rim I3 is substantially symmetricallydisposed with respect to the web 12 and provides a pair of outwardlyextending annular flanges I5, each provided with an underneath lockingface It. A passage I8 (see Figs. 2, 3 and 4) extends in a radialdirection through the rim [3 and part way through the web l2. An airvalve member 19 is threaded into an aperture 20 in the web portion l2and this aperture 29 communicates with the radial passage I8. The valvemember 19 may be a conventional valve member of the type employed inautomobile tires, through which air is inserted for inflatin the tires.A removable cap 2| is provided on the open end of the valve member [9.

Mounted over the rim I3 is a flexible band 22 of rubber or likemate-rial that can be inflated with air. This band 22 is adapted to slipover the rim l3 and is provided with looking portions or heads 23 thatare adapted to rest against the underneath face of the correspondingflange it. The edges of the flanges l5 are rounded to accommodate theband 22. A locking ring 28 is provided for each side of the wheel, eachring being adapted to clamp one side of the band 22 against the adjacentflange l5 of the rim 13. Each locking ring 24 is provided with ashoulder portion or head 25 that engages the corresponding lockinportion or head 23 of the band 22. Each locking ring 24 is furtherprovided with a flange portion 26 and these flange portions 26 togetherwith the web l2 of the wheel are apertured as at 21 to receive aplurality of bolts 28 that pass through the flanges 26 and the web I 2.The bolts 28 are provided with nuts 29 which draw the locking rings 24tightly against the web l2 of the wheel [0. When the locking rings 24are thus secured tightly to the web [2 of the wheel the band 22 isfirmly clamped in place on the rim l3.

Mounted circumferentially about the wheel thus formed is a molded band30 that has a width greater than the distance between the outermostedges of the assembled locking rings 24. Thus there is provided a wheelhaving a band 38 that provides a tread portion and by introducing airthrough the valve member and the passage it the band 22 becomes inflatedwith air that is disposed between the inner face of the band 22 and theouter face of the rim l3. By thus inflating the band 22 the molded band30 is held in the flat poported on all sides. the vertically or radiallextending portions of sition shown in Figs. 2 and 4 or may in fact bevery slightly arched outwardly with respect to the wheel II]. Anabrasive band 3| may then be mounted over the molded band 30 and thewheel is then in condition for use as a sanding wheel, the abrasive bandbeing mounted over the molded band before the band 22 is inflated.Pressure applied against the sanded surface of the wheel is thusresisted by the air cushioning behind th inflated band 22. The fact thatthe locking portions 23 are urged firmly against the underneath faces ofthe flanges 15 of rim l3 securely holds the band 22 on the rim [3 andprevents creeping or circumferential slipping of the band 22 about thewheel II]. It is to b noted that the underneath faces l6 of the flangesl are disposed in wedge-like relationship with respect to the lockingrings 24 so that the locking portions 23 of the band 22 are in factwedged between the looking rings 24 and the flanges I5 of rim l3. Thus,it will be seen that the inflatable band 22 is sup- It is supportedlaterally by V a sanding wheel it is recognized that it can also beprovided with a polishing or bufling face in place of the sanding bandand also there is provided a pneumatic wheel that i useful on smalltrucks, push carts, or other such small vehicles where an inflated wheelis desired.

The device herein described is uniformly balanced and a perfect seal forthe air backing the band 22 is provided by virtue of the effectiveclamping arrangement. The wheel portion I0 may be die cast of aluminum,or the like, and thus the assembled device can be relatively light inweight.

I claim:

1. A pneumatic sanding drum comprising a wheel including a hub, a webextending around said hub and supported thereby, a rim extending aroundthe web and supported thereby, said rim having flanges extending on eachside of the web; an inflatable band fitted over said rim and an outertread member mounted over said inflatable band for supporting a flexibleabrasive band thereon, said band having beaded dges engaging theunderside of the flanges On each side of said .web; a clamping ring foreach side of the inflatableband, said rings being clamped to the web andhaving gripping portions extending laterally of; the web, said portionshaving a bead for engaging the corresponding bead on the inflatable iband so as to stretch said beaded edges towards the web and clamp theband around the rim when the clamping ring is tightened, therebyincreasing the area of sealing contact of said band with said rim; eachring also having a portion extending radially from said lateral portioninto contact with said tread and forming lateral support for ,saidinflatable band, so that said band, when inflated, is clamped betweensaid rim and said rings in a lateral direction, and between said rim andsaid tread in a, radial direction, said web having means for admittingair to the interior of the inflatable band to inflate the same.

2. A pneumatic sanding drum comprising a wheel including a hub, a webextending around said hub and supported thereby, a rim extending aroundthe web and supported thereby, said rim having flanges extending on eachside of the web, the side edges of each of the flanges being rounded andcurving into the undersurface of each flange; an inflatable annular bandfitted over said rim and extending around said curved flanges; an outertread member mounted over said band for supporting thereon a flexibleabrasive band; said inflatable band having beaded edges engaging,respectively, the underside of the flange on each side of said web; aclamping ring for each side of said inflatable band, said rings beingclamped to the web and having a gripping portion extending laterally ofthe web, said portion having a bead for engaging the corresponding beadon the inflatable band so as to stretch said band around the curvededges of said rim when the clamping ring is tightened; said ring alsohaving a portion extending radially from said lateral portion intocontact with said tread, forming radial support for said tread and alateral enclosure and support for said inflatable band, said band, wheninflated, being supported laterally and radially in all directions, saidweb having means for admitting air to the interior of the inflatableband to inflate the same.

ARTHUR W. MALL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 472,287 Crooker Apr. 5, 1892493,002 Webster Mar. 7, 1893 663,839 Woods Dec. 11, 1900 683,122 KnillSept. 24, 1901 691,104 Blodgett Jan. 14, 1902 704,509 Cadman July 15,1902 1,487,256 Mall Mar. 18, 1924

